This final image shows using only Spec maps, again one is Aztec, the other the blocks for the hull, and the image on the right shows what happens with the block-plate map in both Spec and Reflection channels.

If you can, look closely especially at the outer rim of the saucer--the distortions that do not appear when the maps are used for bump only or Reflection only!  This seems to be very odd to me.!